Changes in Microbiological and Physicochemical Quality of Dried Persimmons (Diospyros kaki Thunb.) Stored at Various Temperatures

Abstract

This study was conducted to investigate the microbiological, physicochemical, and visual quality of dried persimmons (Diospyros kaki Thunb. cv. Cheongdo-Bansi) during storage at various temperatures in order to determine the shelf-life. Two commercial dried persimmon samples were evaluated for changes in weight, moisture content, color, texture (hardness and gumminess), and microbial populations during storage at different temperatures (−20, 5, 12, and 25°C) for 70 days. Overall, dried persimmon-2 showed lower levels of total mesophilic bacteria, Escherichia coli, coliforms, yeasts, and molds than dried persimmon-1. Among the physicochemical qualities, significant differences were observed in color parameters such as L∗, a∗, and b∗ of the dried persimmons. However, no significant differences in weight, moisture content, and texture were observed in dried persimmons during storage for 70 days. Thus, changes in visual appearance and color index such as chroma value and browning index can be used as indicators for determining the shelf-life of dried persimmons.

Physical, Microbial, and Chemical Quality of Hot-Air-Dried Persimmon (Diospyros kaki) Chips during Storage

“…Given that individual chips of Preparations 2-5 and 6-10 weighed on average 2 and 6 g, respectively, this places the persimmon chips well within the acceptable range for microbial load in published quality standards which specify that mesophilic aerobic bacteria should be below 10 5 CFU/g (Ireland, Israel) and molds below 10 2 CFU/g (Israel) in similar dried fruit products [22]. As was expected based on the different a w s of the products, the dried persimmon chips in this study exhibited much lower microbial loads than those observed in semidried persimmons with a w s in the range of 0.77-0.83 [9].…”

“…During drying, the characteristic astringent mouthfeel of the fruit decreases, and a powdery white coating of sugar (primarily glucose and fructose) develops on the exterior of the product [8]. Recent work has been done to characterize the shelf-life of hoshigaki (water activity (a W ) 0.77-0.83) at different storage temperatures [9]. However, low-moisture (a W near 0.45), hot-air-dried persimmon chips have not yet been explored in this way, and the sugar bloom phenomenon has not been investigated for this product.…”

Changes in the Physico-Chemical Properties of Persimmon (<i>Diospyros kaki </i>Thunb.) During Drying and Quality Deterioration During Storage

“…The most important factor in food storage management is temperature, with lower temperatures generally extending the storage life by minimizing nutrient losses and property changes (Perera, 2005). During an investigation of the microbiological, physico-chemical, and visual quality properties of dried persimmons of the cultivar "Cheongdo-Bansi" during storage at various temperatures, Hyun et al (2019) found that the visual appearance and color index were useful indicators for determining the shelf life of the product. The two main methods that are available for preserving the quality of dried persimmon fruit during storage are frozen storage and storage under low temperature conditions in the presence of an oxygen scavenger, which is generally used in dried persimmon preservation, because the low temperatures prevent microorganisms from growing and slow down chemical activity, delaying degradation of the fruit.…”

Kinetic Modeling of Quality Changes and Shelf Life Prediction of Dried Coconut Chips

“…According to Dak et al [12], the kinetics of quality parameter change in dried pomegranate arils was zero-order, and the shelf life was predicted to be between 96 and 187 days under accelerated storage conditions based on chemical parameter changes. Hyun et al [13] examined the quality and shelf life of dried persimmons based on the color parameter during storage. Meanwhile, according to Phothapaeree et al [14], the kinetic browning behaviors of ∆E can be utilized to evaluate the shelf life of dried bananas.…”